One of the suitable methods to reducing explosion effects is soil improvement. The foundations on the ground with loose and saturated clay, are susceptible to large settlement and failure, and for soil improvement, need to reinforce the some resistance parameters such as soil stiffness. In this study, Rammed (RAP) and Un-rammed (UAP) Aggregate Pier are used for the soil improvement. Numerical modeling is carried out using PLAXIS axisymmetry model. To model the pier material, constitutive model of hardening soil (HS) and for improved soil, Modified Cam-Clay (MCC) and HHardening Soil (HS) models are used. According to the assessment of parameters, it was observed that increasing the diameter of rammed aggregate pier and length of un-rammed aggregate pier, has better efficiency to improve the bearing capacity and settlement. Finally, the settlement of foundation is reduced with rammed aggregate pier up to 66 percent, and with un-rammed aggregate pier up to 52 percent.